Probiotics, including foods or supplements containing “friendly” bacteria that normally inhabit the digestive tract (usually Lactobacillus or Bifidobacterium), may help prevent colds, a recent study suggests.
A review of 10 studies involving data on more than 3,400 participants ranging in age from infants to adults in their 40s showed that taking probiotics for more than a week was associated with 12 percent fewer colds.
However, the review, by researchers at China’s Sichuan University, found no evidence that taking probiotics could reduce the duration of colds. The only side effects seen among participants in the 10 studies who took probiotics were vomiting and flatulence, but these symptoms were equally as common in the studies’ control groups.
The researchers noted that three previous investigations have examined how probiotics influenced upper respiratory infections in older adults. One found no reduction in incidence among those who took probiotics, but did report that the colds didn’t last as long. Another found a 3.4-fold reduction in the risk of catching a cold or the flu, and the third found that upper respiratory tract infections had a shorter overall duration in those using probiotics compared to those who didn’t use them.